Internal-combustion engine



Feb. 25, 1 930. a w, THOMPSON 1,748,254

INTERNAL COMBUSTION ENGINE Filed Nov. 1926 3 Sheets-Sheet INVENTOR ATTORNEY Feb. 25, 1930. s, w, THOMPSON 1 ,748,254

INTERNAL COMBUSTION ENGINE Filed Nov. 4. 1926 3 Sheets-Sheet 2 WflTE/i WMERF r Z0 26 Z 25 z y l r Z6 flwflm 21 '0/ Warm t} 4 WATER INLET 5 wars ounEr WflTE/ 'INVENTOR D BY M20 4 WTTQR EY Patentecl Feb. 25, 1930 PATENT OFFICE i SETH WALDO THOMPSON, OF MON'ICLAIB, NEW JERSEY INTERNAL-COMBUSTION ENGINE Application filed November 4,1926. Serial No. 146,195.'

My invention relates to improvements in internal combustion engines in which slide valves are moved positively past ports in the cylinder wall at a speed of one complete rewaciprocation of the valve to four turns of the crank shaft instead of the one to two movement of the ordinary poppet valve engine and it is my object'to provide such engines with valves which will be self-seating and always tight, thereby eliminating grinding, and which -wi:llybe freefrom undue wear'and binding, to providepositive means for operating such valves wherebyspring returns are eliminated so thatthe timing remains constant and quiet at all speeds instead of varying with the spring lag, to provide a compression and combustion space of greater efficiency, to locate the means for holding the valves to their seats outside the combustion space andaway fromthe heat while the operating neans are within the cylinder walls and crank case so that no moving parts are exposed, to provide automatic compensation for valve and seat Wear, to provide for the efficient' cooling of the engine, to permit the full and free flow of the gases'into and outof the cylinder, to reduce the cost of construction and increase the efiiciency of such engines and to eliminate a large number of parts 39 presentin poppet valve engines and to so construct the valve mechanism that-but a small amount of power will be required to drive it.

I do not limit myself to the precise mechanism shown in the accompanying drawing in whichil have shown my invention embodied in a single cylinder, four cycle engine it being obvious that it may be applied to multi-cylinder engines.

Fig. 1 is a vertical, sectional view of the engine; Fig. 2 a sectional view of the structure of Fig. 1 on the line 22 thereof; Fig. '3 a detail view, partly in section, of the cylinder head, cylinder, valves and piston; and Figs. 4 to 11 inclusive, diagrammatic views of the crank shaft, piston and valve move- I 'me'nts illustrating how the valve motion is one to four with respect to the crank shaft instead of the usual one to two.

The engine comprises a crankcase 1 in which is mounted the crank shaft 2 and valve drive shafts 3 and 4c. As shown, the crank shaft 2 carries a gear 5 meshing with gears 6 and 7 on the .valve drive shafts 3 and 4 so that the valve drive shafts will'make one revolution to four revolutions of the crank shaft, but other driving means may be substituted for the gears.

The cylinder 10 contains the piston 11, withthe connecting rod 12. The bore of the cylinder is enlarged. at the upper end 13 as shown in Figs. 1, 2 and 3 to form the valve seats.

The intake valve 15 and exhaust valve 15' are duplicates and may be made by turning a cylinder and splitting it longitudinally. These valves have their outer faces machined to fit the enlarged bore of the cylinder at 13 and each contains ports 1616 adapted to aline with the ports 17- 17 in the cylinder walls, the valve faces above and below the 7 valve ports being adapted to slide over and close the cylinder ports. These ports are preferably made relatively large so that the free ingress and egress of the gasesccan be accomplished. In practice these port open- 7 ings maybe greater than poppet valve open-- ings in engines of the same bore and stroke to permit the easier flow of gas. Each valve has a stem 1818' adapted to extend through a slot 1919 in the cylinder wall and these stems are preferably flattened at 20-20'.

The cylinder wall is bored at 2121 to receive the valve actuating rods 2222", which are reciprocated by any suitable means, connecting rods 23-23" on the valve drive 8 shafts 3 and 4t being shown. The upper ends, of the rods 22-22 are slotted at 24-24 to receive the flattened portions 2020 of the valve stems, which are a sliding fit therein. The flattened portion of the valve stems may also be a'sliding fit for the cylinder slot if desired. This construction prevents any tendency of the valves to twist on their seats. Springs 2525 are slipped over the valve stems outside the cylinder walls and adjusting nuts 2626 serve to control the compression of the springs and to hold the valves to their seats in the enlarged bore of the cylinder with any desired degree of pressure. These springs, being resilient, automatically take up any wear in the valves or seats and excessive wear may be taken up by slightly moving the nuts 2626'.

The cylinder head 30 has an extension 31 passing down into the cylinder with a spark plug hole 32 located in the bottom ofthe recess 33, the head extension overlapping the valves but not in contact therewith so that the compression space is an annular and cylindrical space combined with the spark plug Well to the center of the combustion space instead of being at one side thereof. This construction obviates the usual junk rings in the cylinder heads of slide valve engines and the pe culiarly shaped compression space has been found to be very efficientin practice.

l/Vater jackets maybe formed in the head and cylinder walls or the engine may be air cooled as desired. I

. In the operation of the preferred form of engine shown in the drawings the upper part of a valve will close ed the cylinder port, then the valve port will aline with the cylinder port and finally the lower part of the valve will close olf the cylinder port so that the cylinder ports are opened and closed twice on each complete reciprocation of the valve, thereby cutting the valve movements in half for a given number of revolutions of the crank shaft. It requires one revolution of the crank shaft of a poppet valve four cycle engine for the intake and compression strokes and a second revolution of the crank shaft for the power and exhaust strokes during which time the cam shaft has made four revolutions while in my engine the valve driving shafts will make but one revolution to four revolutions-of the crank shaft and the valves will have made one complete reciprocation. In other words one revolution of my valve drive shaft and one complete reciprocation of my valves will carry my en ine through two complete cycles thereby reducing the power to drive the valves and resulting in very quiet operation.

To more clearly illustrate this result Figs. 4 and 5 show the intake and compression piston strokes during the first revolution of the crank shaft. Figs. 6 and 7 show the power and exhaust strokes during the second revolution of the crankshaft and during this time the valve driving shafts have made a half revolution and moved the valves in one direction to cover and uncover the ports in the cyl inder. In Figs. 8 and 9 the crank shaft has made the third revolution on the intake and As the cylinder and its enlarged bore up wear.

forming the valve seats are concentric and the valve faces are arcs of-circles the cost I heat of the power stroke and the exhaust valve stem is not exposed to the hotgases.

As the. valves are positively driven in both directions the timing will be constant at all speeds as spring lag is not involved in their operation. As the valve stem slides freely in the slots in the cylinder and valve rods the spring will at all times hold the valvefirmly but lightly on its seat and automatically take i As thevalves are light inweight and have no springs in connection with them the power required to drive them is very small. It should be noted that the exhaust valve does not have to encounter the presunder cover and inside the'engine, although a without the compression space, the actual valves only excepted, they may be easily lus b'ricated and are not exposed to dust dirt and undue heat which would cause wear a'nd'sticking. This results in an engine which openates quietly, has a long life and has no moving parts in sight.

It is obvious that the valves may be moved I by means other than the crank throws and connecting rods shown and described and that various other mechanical movements may be substituted for those shownfa'nd described without departing from the scope of my invention and I do not limit myself to the spe 'cific mechanism shown in the. drawing and described herein.

I claim i A 1. In an internal combustion engine, a cylinder provided with a slot and a-port in the wall thereof, a valve seat adjacent said port and slot, a slide valve ion said seat provided with a centrally located port adapted to aline with the cylinder port, the extensions on either side .of the port adapted to close the cylinder port, a Valve stem on said valve ex- 1 tending through the slot, means on said stem without the cylinder for'resiliently holding lie to aline with the cylinder port, the extensions on either side of the port adapted to close the cylinder port, a valve stem on said valve extending through the slot in the cylinder wall, a spring on said stem without the cylinder, an abutment on said stem against which said spring is compressed and for reciprocating said valvemeans B 3. An internal combustion engine comprising a cylinder provided with a port and slot in the wall thereof, a piston in said cylinder,

a crank shaft and a connecting rod, a valve seatadjacent the port and slot, a slide valve on said seat provided with a centrally located port adapted to aline with the cylinder port, the extensions on either side of the valve port adapted to close the cylinder port, means extending through the slot for holding said valve to its seat and means for imparting one complete reciprocation to the valve for each four revolutions of the crank shaft.

4-. An internal combustion engine comprising a cylinder provided with a port and a slot in the cylinder wall, a piston in said cylinder, a crank shaft and a connecting rod, a valve seat adjacent said portand slot, a slide valve on said seat provided with a centrally located port adapated'to aline with the cylinder port,

the extensions on either side thereof adapted .to close said cylinder port, means extending through the slot for holding said valve to its seat, said means being located wholly outside the combustion space, a valve drive shaft, means for revolving said shaft once to each four revolutions of the crank shaft and a valve rod connected to said valve and valve drive shaft whereby the valve is reciprocated.

5. An internal combustion engine comprising a cylinder provided with a port and a slot in the wall thereof, a piston in said cylinder, a crank shaft and a connecting rod, a valve drive shaft, a valve seat in the cylinder adjacent the port vand slot, a slide valve on said seat provided with a centrally located port adapted to aline with the cylinder port, the extensions on either side thereof adapted to close the cylinder port, a stem on said valve extending through the slot, a spring on said stem, without the cylinder, an abutment on the end of the stem compressing the spring, a

- valve rod provided with a slot through which the valve stem passes and against which the end of the spring bears and means connecting the valve rod and valve drive shaft whereby the valve will be reciprocated on the revolution of the valve drive shaft.

6. An internal combustion engine comprising a cylinder provided with a port and a slot in thewall thereof, a piston in said cylinder, said cylinder having an enlarged bore adjacent the port and slot, forming a valve seat, a valve onsaid seat provided with a centrally located port adapted to aline with the cylinder port, the extensions on either side thereof adapted to close the cylinder port,

ported, slotted cylinder, a valve seat in the combustion space adjacent the port and slot, a slide valve therein, a stem on said valve extending through the slot, resilient means on said stem and without the combustion space for holding said valve on its seat and means for reciprocating said valve.

8. In an internal combustion engine, a ported, slotted cylinder, a valve seat in the combustion space adjacent the port and slot, a slide valve therein, a stem on said valve extending through the slot, resilient means on said stem and without the combustion space for holding said valve on its seat and means for reciprocating said valve said reciprocat- L signature.

S. WALDO THOMPSON. 

